Nutrients often become a little deficient during flower and the plant will pull N, P, K and Mg from other plant parts, like lower leaves. You can feed them a little more, but don't over-do it.
Don't expect the yellow leaves to ever "green up" again. At best, you can stop further yellowing. I had a strain that I grew once that just cannibalized its lower leaves and it didn't seem to care about added nutrients, so those strains exist.
Nutrients often become a little deficient during flower and the plant will pull N, P, K and Mg from other plant parts, like lower leaves. You can feed them a little more, but don't over-do it.
Don't expect the yellow leaves to ever "green up" again. At best, you can stop further yellowing. I had a strain that I grew once that just cannibalized its lower leaves and it didn't seem to care about added nutrients, so those strains exist.
How big are the pots?
I have a couple look just like that. I think mine are way too big for the 2 gal pots for one thing. I have to water every day. I think I mistook the burnt leaf tips for overfeed then cut back on nutes and it got worse. Now I think the burnt tips are the start of K deficiency from nute lockout. The runoff ph was 5.6 so I added lime to bring it up.